In particular, the invention deals with a method which comprises:                a) providing a respiratory equipment including:                    a respiratory mask having a front side and a rear side (at the opposite of the front side), the respiratory mask comprising a cavity having an opening in the rear side, the rear side of the respiratory mask being adapted to be applied on a user face in a use position in which the user face closes the opening of the cavity,            an inflatable harness adapted to maintain the respiratory mask against the user face, and            a storage element comprising a housing adapted to store the respiratory mask in a storage position,                        inserting the respiratory mask into the storage element so as to place the respiratory mask at a storage place of the storage element.        
The respiratory mask typically worn by aircraft crewmembers must be attached surely and rapidly on the crewmember head. And it must require only one hand to be attached; since the other hand of the user is frequently required for some other essential tasks.
For example, if because of a pressurization failure, the pilot of an aircraft is required to rapidly don his respiratory mask to provide him with the necessary oxygen for breathing, he often must do so with one hand while his other hand is occupied in controlling the aircraft. Thus, the use of an inflatable head harness has been suggested in order to enable the respiratory mask to be donned using only one hand. Generally, the head harness has substantially a dome shape or an annular shape and is expanded diametrically by the introduction of pressurized gas to cause the harness to increase in size so that it can be positioned over the head of the user. The gas flow is controlled by a valve attached to the respiratory mask, and, after enlargement of the harness, the respiratory mask is placed in position against the face of the user, with the harness extended over and spaced from the back of the head. Once the respiratory mask is properly positioned, the pressure in the harness is released, causing the harness to contract and to contact the head of the pilot, whereby the respiratory mask is securely held in its proper position. Meanwhile, the other hand of the pilot is free to control the aircraft or to perform such other tasks as may be required.